Science of Synthesis

Kündig, E. P.; Pache, S. H., Science of Synthesis, (2003) 2, 157.

The earliest synthesis of bis(benzene)chromium(0) (‌1‌, M = Cr; R1 = H) and mixed benzene/biphenyl analogues goes back to 1919, when Hein treated anhydrous chromium(III) chloride in diethyl ether with phenylmagnesium bromide. It was only in 1954, however, that these compounds were recognized as being π-complexes. A mild reductive methodology is of preparative value for the naphthalene complexes. The chromium and molybdenum complexes ‌2‌ (M = Cr, Mo) as well as methyl-substituted derivatives are obtained by potassium evaporation into a solution of molybdenum or chromium halides and naphthalene in tetrahydrofuran.[‌19‌] Alternatively, the sandwich complexes are obtained by reaction of molybdenum(V) chloride or bis(tetrahydrofuran)molybdenum(IV) chloride and the arene with a highly reactive slurry of magnesium in tetrahydrofuran.[‌16‌] The involvement of arene radical anions in these reactions is probable. Indeed, as shown by Ellis and co-workers, naphthalene sandwich complexes ‌2‌ (M = Cr, Mo) are accessible in 20–25% yield via reaction of alkali metal naphthalenides with tris(tetrahydrofuran)chromium(III) chloride, tris(tetrahydrofuran)molybdenum(III) chloride, or bis(tetrahydrofuran)molybdenum(IV) chloride.[‌20‌]

Mee eeeeeee eee eee eeeeeeeeee eeeeeeeeeee, eee eee(eeeee)eeeee eeeeeeeee ee eeeeeeee, eeeeeeeeee, eee eeeeeeee (e.e., ‌8‌, M = Me, Me, M; M8 = M, Me) eeee eeee eeeeeeeeeee ee eeeeeee e eeeee eeeeee eeee eeeeeeee eeeeee ee eee eeeeeeee ee eeeeeeee eeeeeeeeeee eee eee eeeee (Meeeeee–Meeeee eeeeeeeee; ‌Meeeee 8‌). Mee eeeeee ee eeeeeee ee eeeeee eeeeee eeee eee eee eeeeeeeeee eeeeeeee eeeee Meeeeee–Meeeee eeeeeeeeee. Mee eeeeeeeee eeeeee eeeeeeee eeeeeeeee [M(eeeee)8][MeMe8] eee eeeeeee eeeeeee ee eee eeeeeee 88-eeeeeeee eeeeeeeee ee eeeeeee eeeeeeeeee (eee eeeeeeee) ee ee eeeeeeee eeeeeeeeeeeeeeeeee eeee eeeeeeeee (eee eeeeeeeeee eee eeeeeeee). Meeeeeeeee, eee eeeeeee eeeeeeeee eee eeeeeee eeeeeeee ee eee eeeeeee. Mee e eeeee eeeee, eeeeee ee eee Meeeeee–Meeeee eeeeeeeee eeeeeeee ee eee eeeee Me > Me >> M. Mee eeeeeeeee ‌8‌ (M = Me, Me, M; M8 = M) eeee eee eeeeeeee ee 88% eeeee eee eee eeeeeeee eeeeeee,[‌88‌] 88% eee eee eeeeeeeeee eeeeeee,[‌88‌] eee 8% eee eee eeeeeeee eeeeeee.[‌88‌] M eeeeeeee eee-eee eeeeeeeee eeeeeeeee eeeeeeeee ee eeeeeeee eee eeeeeeeeee eeeeeeeee eeee eeeeeeee/eeeeeeee eeeeeeeeeee ee eeeeeeeee eeeeeee eeeeeeee ee eeeeeeeee eeee eeeeeeeeeeeeeee eeeeeee eee eeeeeeee eeeeeeee eeeeeee ‌8‌ (M = Me; M8 = Me) ee eeeeeeeeeeee eeeee eee eee eeeeeeeeee eeeeeeee ee 88% eeeee.[‌88‌] Meeeeee eeeeeeeeeeee eeee eeeeeeeeeeeeeeee ee eee eeeeeeee eeeee ee eeeee ee eeeeeeee/eeeeeeee eeeeeeeeeee.[‌88‌]

‌Meeeee 8‌ Meeee–Mee(eeeee) Meeeeeeee Meeeeeee ee eee Meeeeee–Meeeee Meeeee[‌88‌,‌88‌]

Meeeeeeeeeee Meeeeeeee

Mee(η8-eeeeeee)eeeeeeeeee(8) (‌8‌, M = Me; M8 = M); Meeeeee Meeeeeeee:[‌88‌]

Mee eeeeeeeeee eeee ee ee eeeeeee eee ee e eee, eeeee eeeeeeeeee eeeee Meeeeee eeeeeeeeee. Meeeeeeeeeeee eee ee eeeeeee eeeeeee ee eee, eee [Me(η8-M8M8)8] ee eeeeeeeeeee eeeeeeeeee ee eeeeee. MeMe8 (88 e, 888 eeee), eeeee MeMe8 (888 e, 8888 eeee), eee Me eeeeee (8.8 e, 888 eeee) eeee eeeee ee e 888-eM eeeee-eeeeeeee eeeee. Mee eeeeeee (888 eM) (MMMMMMM: eeeeeeeeee) eee eeeee eeee e eeeeee ee 88 eee (eeeeeeeeee eeeeeeee). Meeee eeeeeee ee ee, eee eeeeeeeeee eeee eeeee ee eeeeeee eee e eeeeee eeeeeeeee eee eeeee. M Meeeee eeeeee eee eeee ee eee eeeee eeeee ee eeeeeee ee eeee eeeeeeee. Mee eeeeee eeeeeeeee eee eeeeeee eeeee ee eee eeeee, eee eee eeeeeeeee eee eeeeeeeee ee e M8 eeee eeeeeeeeee e Me eeeeeee eeee e eeeeeeeeee Me eeeee ee eeee ee eeeeee eeeeeeee ee 888–888 Meee. M eeeeee eeeeee eee eeeeee ee eeeee ee eee eeeeeeeee, eee M8 eeeeeeee eee eeeeeeeee eeeee e eeee eeeeee ee eeeeeee eee eeeeeee eeee eee Me eeeeeee, eee eee eeeeeeeeeee eee eeeeee eeeeee ee 888°M. Meeee 88 e ee eeeeee, eee eeeeeeeee eee eeeeee ee ee, eee eee eeeeeeee eeee eeeee ee eeeeeee. Mee eeeeee eee eeee eeeeeeeee eee eeeeeee 88 e. Meeee eeeeeee ee ee, ee eeee ee eeeeeeee ee eee eeeeeee eeee eee eeeeeeee. Mee eeeeeee eee eeeeee eeee eeeeee (8 × 888 eM) eee eeeee eeeee eeeeee. M 8-M, eeeee-eeeeee eeeee eee eeeeeeee eeee e eeeeeeee eeeeeeee eee eee e M8 eeeee. Me MMM (888 e ee 8888 eM M8M) eee eeeee eee eeeeee eeee eee ee eeeeeeee M8 eee 88 eee. Mee eeee eee eeeeee ee −88°M eee eee eeeee eeeee eeeeeeee eeeeee eee eeeee ee eeeee eeeeeeee eeee eeeee 8 e, eeeee e eeeeee M8 eeeeeeeeeeeeee (eee eeeeeeeeeee eee eeee eeeee −8°M). Meeee eee eeeeeeee eee eeeeeeee, eee eeeeeee eee eeeeee eeeeee ee ee eee eeeeeee eee eeeeeee 8 e. Mee eeeeeeee ee eee eeeee eeee eeee eeeeeeee ee e eeeee eeeeee eeee e Meeeee eeee, eee eeeee eee eeeeee eeee M8M (888 eM), eee eeeee eeeee eeeeee. (MMMMMMM: Mee eee eeeee ee eeeeee eeeeeeeeee.) Mee eeeee eee eeeeee eeeeeeeeee eee eeeeeeeee eeee eee eeeeeee (8 M ee eeeee). Mee eee eeeeeee eeee eee eeeeeeee, eee eeeee eeeeeeee eeeeeeeeeeee ee 888 eM, eee eeeeee ee 8°M eee 8 e. Mee eeeeee eeeee eeeee eee eeeeeee ee eeeeeeeeee, eeeeee eeee eeeeeeeee eeeee (888 eM), eee eeeee eeeee eeeeee; eeeee: 88.8 e (88.8%).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88-8, 888.